Refrigerating apparatus



June 18, 1940. J. c. CHAMBERS REFRIGERATING APPARATUS 5 Sheets-Sheet 1 3\J. do 1 m B i t j K c w w m 3 -1 v i 11min: ..\H

June 18, 1940. J. c. CHAlMBERS REFRIGERATING APPARATUS Filed Dec. 27,1933 3 Sheets-Sheet 2 ggfi. 2 K NTOR I ATTORN J. c. CHAMBERSREFRIGERATING APPARATUS:

June 18, 1940.

Filed Dec. 27, 1933 3 Sheets-Sheet 3 a? 2 W ATTORNEEY Patented June 18,1940 UNITED STATES PATENT OFFICE REFRIGERATING APPARATUS ApplicationDecember 2'7, 1933, Serial No. 704,164

11 Claims.

This invention relates to the conditioning of air.

It is among the objects of this invention to provide a method andapparatus for conditioning air in which desirable temperature andhumidity conditions are maintained notwithstanding variations in thetemperature and/or humidity loads placed on the apparatus.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being hadto the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

Inthe drawings:

Fig. 1 is a horizontal cross-sectional view, somewhat diagrammatic andtaken along the line i-l of Fig. 2, of an apparatus embodying featuresof my invention;

Fig. 2 is a vertical cross-sectional view similar to Fig. 1;

Fig. 3 is an enlarged view showing a detail of one form of dampermounting;

Fig. 4 is an end view of a portion of the apparatus shown in Fig. 3; and

Fig. 5 is a view of a detail of the form of damper mounting for dampersnot directly connected to motors.

In practicing my invention, air is supplied to an enclosure it, the airbeing conditioned to produce the desired temperature and relativehumidity conditions in the enclosure II. This is accomplished by causinga stream of air to flow through a plurality of air modifying zones orunits Ii and I2 and in varying the character of flow through these zonesor units and/or the air modifying intensity of the units so that thedesired temperature and humidity conditions are produced in theenclosure l0.

The two or more zones or units II and I! are so arranged with respect toeach other that air may flow through these units partly orwhplly in aseries relation, partly or wholly in a parallel relation or with a.varying proportion of the stream flowing in series relation and anotherportion flowing in parallel relation. To this end, the zones or units IIand II are preferably arranged in a staggered relationship as showninFig. 1, with one of the units, in this case ll, nearer the enclosure itthan the other of the units. The means for varying the character of flowof air through the units may take the form of damper means comprising aset of .dampers l3, ll, Ii

and I6 operatively linked together so that they may assume variouspositions -as indicated in fullanddottedlinesinFlg. 1. Whenthedompershave the position shown in full lines in Fig. 1, the nature of the flowof air is substantially wholly a series flow. When they assume theposition indicated by the letter a, the nature of the flow is partly inseries and partly in parallel. 5

And when the position of the dampers is that indicated by letters b, theflow of air through the units is substantially a parallel one. That is,one in which the various portions of the air stream flowing through thezones or units do not pass 10 through both zones or units- The means bywhich the dampers are caused to assume the various positions arehereinafter more fully described.

The zones or units H and I2 may be air modi- 15 parallel relationship,and returning through the 25 evaporated refrigerant line 20 to thecompressor 25. The automatic expansion valves l8 and i9 may becontrolled by thermostatic bulbs 2i and 22 respectively to maintain thecoils in a substantially flooded condition as will readily be under- 30stood by those skilled in the art.

The nature of the load on the air conditioning apparatus varies fromtime to time withrespect to the requirements for dehydration and coolingof the air. for these variations. This is accomplished by varying thenature of the flow of air through the air conditioning apparatus in themanner heretofore described and under the automatic .control of theconditions in the enclosure i0 and in varying the air modifyingintensity or power, of! the apparatus. To this end, a snap acting wetbulb thermostat (or relative humidity hydrostat) 30 and a snap actingdry bulb thermostat 3|v may be placed in any position to be afiected by45 the general condition of the air in the enclosure (ll. These controlsare connected to the air conditioning mechanism to vary the operationthereof in order to maintain the proper conditions in varies, at times,the air modifying intensity or power of the units I l and H. Toaccomplish this,

it controls the motor 31 which drives the compressor 25 and causes it tostart and stop, which in turn varies the cooling power of the units HMeans are provided to compensate and I2 in a manner to tend to maintainthe dry bulb in the enclosure IIl within predetermined limits. The wetbulb thermostat 30, which is responsive to humidity conditions in theenclosure, may also vary the air modifying intensity of the units II andI2 and is therefore also connected to the motor 32 to cause thecompressor 25 to operate and tend to maintain the relative humidityconditions in the enclosure I0 below a predetermined limit. Thecompressor 25 is caused to operate whenever the arm 34 contacts at 35ain response to an increase in the wet bulb tem perature in the enclosureIII. The controls 30 and Ill are in parallel electrical connection Withthe motor 32, and either one of the controls can cause the motor tooperate, and the motor will continue to operate so long as eithercontrol maintains the circuit closed. Thus the compressor 25 operates solong as either the dry bulb or the wet bulb temperature is above itsrespective predetermined maximum limit, and tends to reduce eithertemperature below its said maximum limit.

In addition, the wet bulb thermostat 30 controls the nature of the flowof air through or past the units II and I2 to modify the dehydratingcapacity of the apparatus. Preferably the flow of the stream of air issuch that it has a substantially constant volumetric capacity throughthe air conditioning apparatus, and the length of contact betweenportions of said stream and the combined cooling surface or zone ofunits II and I2 is varied to produce the necessary dehydrating action onthe stream. In general, when the nature of the contact is longer, aswhen the stream flows wholly or largely in series through the units IIand I2, the dehydrating action is greater; and, conversely, when thenature of the flow is Wholly or largely in parallel, the dehydratingaction is decreased. Thus by varying the nature of the air flow throughthe units II and I2 in accordance with the humidity conditions in theenclosure I0, the humidity conditions can be controlled or maintainedwithin desired or predetermined limits. To this end, the wet bulbthermostat 30 controls the dampers I3, I4, I5 and I6 and causes them toassume the various positions indicated in full and dotted lines inresponse to wet bulb temperatures in the enclosure I0. In oneembodiment, the dampers are mounted on hinged rods which are placedunder the tension of springs M and 42 which exert oppositely directedtortional forces on the rod 40 which are balanced when the dampersassume the position indicated at a in Fig. 1. This may be called theintermediate or normal position of operations. A motor 43 is provided toactuate the dampers I3 and I5 and a-motor 44 is provided to actuate thedamp ers I4 and I6 from the normal position. When the wetbulbtemperature fallsto, or below, a predetermined limit, the arm 34contacts at 36 and closes an electrical circuit leading to the motors 43and 44 and causes the dampers to assume the position indicated at 11,causing the air to flow in a parallel relationship with respect to theunits II and I2. When the air flows in this parallel relationship, thecoils produce the minimum or lesser amount of dehydration of the air,since the various portions of the air stream remain the shortestpossible length of time in contact with a cooling surface. Thus arelatively large amount of air is cooled, but not to as low atemperature as when a larger series flow is produced. It is to beunderstood that,

under these conditions. the compressor 25 may or may not be operatingdepending on the dry bulb conditions. If the dry bulb temperature inenclosure I0 is sufilciently low, the compressor does not operate, andif too high, it does operate. On the other hand, if the wet bulbtemperature is at, or above, the upper desired or predetermined limit,the arm 34 contacts at 35a, and the compressor 25 is caused to operate,if it is not already operating under the control of dry bulb thermostat3|. In addition, the arm 34 contacts at 35 and the dampers assume theposition indicated in full lines in Fig. 1 because the motors 43' and 44are energized to turn in the necessary direction and this causes themaximum amount of series flow in the air stream. Under such conditions,all, or a certain portion, of the air is contacted for the maximumlength of time with the cooling surfaces and this dehumidifies the airto the maximum extent and tends to reduce the wet bulb temperature ormaintain it below a predetermined maximum limit in the enclosure II).

The motors 43 and 44 may be of the stall type. When the dampers reachthe limit of their movement, the motors stall and maintain the dampersat such limit positions as long as the motors are energized, but whenthe motors are de-energized, by the breaking of the contact at the wetbulb thermostat 30, then, these springs M and 42 return the dampers tothe position indicated at a which is an intermediate position. The driveor gear connection between the motors 43 and 44 and the rods 40 may beof any type which permits the motors to overcome the springs as long asthe motors are energized, but permit the springs to return the dampersto the position a when the motors are de-energized. This can beaccomplished either by a proper mutual drive gear relationship betweenthe motor and the rod, causing the motors to stall at the, end of themovement, or it may be accomplished by a slip clutch drive, (magnetic orotherwise) which has a greater power than the springs H and 42 while themotor is operating, (in which case the motors continue to turn untilde-energized) and permits the return of the dampers when the motors arenot energized.

Any means for causing a flow of air past the air modifying zones II andI2 may be provided. This may take the form of a fan 50, driven by themotor 5| to produce a substantially constant volumetric flow of airthrough the air conditioning .apparatus. The intake of the fan may beconnected to a chamber 52 which in turn is supplied with outside freshair through the conduit 53 and is supplied with air from the enclosureI0 through the conduit 54. The air thus enters into the chamber 52,enters the fan 50 and is caused to flow through the air conditioningapparatus contained in the casing 55 and is discharged into theenclosure ID.

A permanent airby-pass 60 may be provided around the air modifying unitsII and I2. This by-pass 60 may be of any desired size, and preferably isof sufllclent size to temper the air conditioned by the units II and I2to prevent undesirable cold drafts in the enclosure ID. This by-pass ispreferably never changed as to size and as to the volume of air flowingtherethrough. Thus a stop 6| is provided for damper I4 to prevent itfrom modifying the size of the by-pass. When the dampers are in positiona dampers I6 and I4 are substantially parallel, but when they areinposition b damper I4 is prevented from turning by stop 6|. A lostmotion 62 is provided in the linkage 63 between dampers l4 and I6through which motor 44 drives damper M to permit this convergingposition between these two dampers. When these dampers are in position btheir converging position tends to compensate for the decreased airresistance through the units due to the parallel air flow and thus tendsto maintain a fixed ratio of air flow through the units II and I2 andthe by-pass 60. The dampers i3 and [5 are provided with a similarlinkage 64 and lost motion 65, for turning damper I5 by motor 43, andwith a stop 66 which aids in compensating for the varying air resistanceat various damper positions and tends to maintain a fixed ratio ofvolumetric flow between the by-pass 60 and the units II and I2.

While the form of embodiment of the in- Vention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:-

1. An air conditioning apparatus comprising two or more air modifyingunits, means for causing a stream of air to pass selectively in seriesor parallel through said units to vary the effect upon the relativehumidity of said air.

2. An air conditioning apparatus comprising two or more air modifyingunits, means for causing a stream of air to pass through said units witha portion of said stream passing in series and another portion passingin parallel, and means for varying the ratio of said portions to varythe effect upon the relative humidity of said air.

3. The method of conditioning air in an enclosure which comprisesflowing a stream of air through a plurality of .air modifying zonesandinto said enclosure with a portion of said stream flowing throughsaid zones in series and another portion in parallel.

4. The method of conditioning air in an enclosure which comprisesflowing a stream of air through a plurality of air modifying zones andinto said enclosure with a portion of said stream flowing through saidzones in series and another portion in parallel, and varying the ratioof said portions in accordance with conditions in said enclosure.

5. The method of conditioning air which comprises flowing a stream ofair through a plurality of air cooling zones with a portion of saidstream flowing through said zones in series and another portion inparallel.

6. The method of conditioning air in an enclosure which comprisesflowing a stream of air through a plurality of air cooling zones andinto said enclosure with a portion of said stream flowing through saidzones in series and another portion in parallel, and varying the ratioof said portions in accordance with conditions in said enclosure.

'7. An air conditioning system comprising, in

combination, a heat absorber, the main function of which is to removeprincipally sensible heat from air flowing thereover, a second heatabsorber adapted to cool air flowing thereover to below the dewpoint'thereof, means responsive to the temperature of the air to beconditioned for controlling the heat exchange between the air and saidabsorbers, means for controlling the flow of air over the secondmentioned heat absorber, and means responsive to the relative humidityof the air to be conditioned for actuating the controlling means.

8. An air'conditioning system comprising, in combination, a heatabsorber, the main function of which is to remove principally sensibleheat from air flowing thereover, a second heat absorber adapted to coolat least a part of said air to below the dew point thereof, meansresponsive to the temperature of the air to be conditioned forcontrolling the heat exchange between the air and said absorbers, meansfor controlling the flow of air over the second mentioned heat absorber,and means responsive to the relative humidity of the air to beconditioned for actuating the controlling means.

9. An air conditioning system comprising, in combination, refrigeratingapparatus including an evaporator, the main munction of which is toremove principally sensible heat from air flowing thereover, a secondevaporator adapted to' cool air flowing thereover to below the dew pointthereof, means for withdrawing gaseous refrigerant from the evaporatorsand for condensing the refrigerant and for delivering the same to saidevaporators, means responsive to the temperature Of the air to beconditioned for controlling the refrigerating apparatus, means forcontrolling the flow of air over the second mentioned evaporator, andmeans responsive to the relative humidity of the air to be conditionedfor actuating the second mentioned controlling means.

10. An air conditioning system comprising, in combination, refrigeratingapparatus including an evaporator, the main function of which is toremove principally sensible heat from air flowing thereover, a secondevaporator adapted to cool at least a part of said air to below the dewpoint thereof, means for withdrawing gaseous refrigerant from theevaporators and for condensing the refrigerant and for delivering thesame to said evaporators, means responsive to the temperature of the airto be conditioned for controlling the refrigerating apparatus, means forcontrolling the flow of air over the second mentioned evaporator, andmeans responsive to the relative humidity of the air to be conditionedfor actuating the second mentioned controlling means.

11. An air conditioning system comprising, in combination, refrigeratingapparatus including an evaporator, the main function of which is toremove principally sensible heat from air flowing thereover, a secondevaporator adapted to cool at least a part of said air to below the dewpoint thereof, means for withdrawing gaseous refrigerant from theevaporators and for condensing the refrigerant and for delivering thesame to said evaporators, means for controlling the flow of air over thesecond mentioned evaporator, and means responsive to the relativehumidity of the air to be conditioned for actuating the controllingmeans.

JEWEL C. CHAMBERS.

